Improved character customization
If there's one thing that Gearbox doesn't seem to realize about its own game, it's that many players find dressing up their characters almost as fun as the core combat. Borderlands is best enjoyed in its cooperative mode, and extensive customization would allow players to distinguish themselves from their peers. We'd like to see more options besides swappable heads and color variations for outfits—instead, let's have entirely different costumes for each character. Just imagine, for instance, how much better Tiny Tina's Assault on Dragon Keep would have been if you were allowed to put on a robe and a wizard hat.